<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>

<script>
   /* (function () {

    })();

    ;(function () {

    })();

    +(function(){})();

    -(function(){})();*/

   (function () {
       var age = 18;
       console.log(age);
   })();

   (function () {
       console.log(age);
   })();
</script>
</body>
</html>